Bulletzzz

Hi Guys
I am new here and I will say from the outset that I am definitely NO expert when it comes to the V design engines (I6 is my speed), however,no.1 son has this 350z that he has managed to run dry of oil once already. That is since solved with $800 in crank machining and 0.50 bearings and last but not least, dear Dad's labour (me).......KIDS!
Getting back to the task at hand now.. My question is this:
What the hell does this circled red part hide beneath it? Even in V8's,I have never seen this.
Any help appreciated.

The mystery part of the block VQ35DE in 350z 2003 coupe. Not my photo.

Ponyryd

I’m no expert but it looks like a coolant passage below it, it looks like it’s permanently blocked and unused, so no worry.

Sundown72

It’s the rear exit for the cooling jacket. In stock form for the 350Z it’s not used. There’s a block off plate and matching gasket.

On the Pathfinder that shares the same block, it has a plate with a neck that’s plumbed into the rear coolant casting that bolts to the back of the heads. The Pathfinder coolant casting has provisions for a thermostat as well. Adding this arrangement to the Z is the “Pathfinder Cooling Mod” and is well documented.

You’ll need the block off plate and gasket. It can’t be left open. It looks effectively useless, but if you pour enough water in there you’ll see it run out the water pump passage of the block.

Good luck.

Bulletzzz

Thanks very much Sundown. Appreciated. I am good as this is not my pic of the block. My block is complete, including said cover plate and gasket.
I will have a look at the mod you mentioned for curiosity though.

Sundown72

Glad to help. Here’s a photo of my block with the pathfinder mod. Be mindful of where you put the water temp sender, it can conflict with the cam sensor plug if you’re too close. This mod also requires cutting the stock coolant return pipe.

Bulletzzz

Cheers Sundown. I am not looking to mod it. I was just curious as to why it was there in the first place. It is the son's 350z so if he wants that kind of ****, he can do it!
I am just looking to get it back together now so he can get out of his mother's car as she wants it back.
I will clean everything up and paint the block in blue like he wants to match the car when he gets it resprayed, and make it all look great so it "pops" when the bonnet is lifted.
Thanks again mate. All the best.